1.25" or 2" Optolong Moon&Skyglow Filter for Astromomical Telescope Eyepieces

Description

Optolong 1.25'' /2" Filter Moon & Skyglow Standard Eyepiece Filter For Telescope
Moon & Skyglow filter is designed to darken the background sky by blocking light transmission from skyglow 589nm and many street light emissions from artificial light. Its high efficiency preserves image brightness, reveals more details and increases contrast of moon, galaxies, nebulae and globular star clusters.
Main Use and Performance
·Ideally it is quite versatile filter for visual observation and astrophotography on planetary nebula.
·WARNING: The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.
Technical Data
·Optical substrate material
·Thickness 2.0mm
·Surface Quality: 60/40 (Refer to MIL-O-13830)
·Fine-optically polished to ensure accurate 1/4 wavefront and <30 seconds parallelism over the both surface
Coating Parameter
·Multi-layers anti-reflection coating
·Non-cementing optical substrate coating
·Electron-beam gun evaporation with Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL(central wavelength) no deviation affected by temperature change
·Planetary rotation system offers precision and homogeneity of coatings ensuring high value on transmission of pass-band and Optical density of off-band
Filter Cell
·Ultra-thin filter cell minimize vignetting by maximize possible clear aperture (clear aperture is 26mm for 1.25”; 45mm for 2”)
·Aerometal Material | Precise CNC Machining | Sand Blasting Process | Black Anodized Finish | Extinction Treatment to Prevent Reflection | Laser Engraving No Fading
Package
·Plastic PP Case | Imported High Pressure EVA Case Lining | Silver Cardboard Box | High Density Sponge Carton Lining
Size
·Standard 1.25” or 2" for choice